我的项目中有3个级别的嵌套.像这样的东西:
public class Assignment { public Element Element { get; set; } } public class Element { public Subject Subject { get; set; } } public class Subject { public int? Id { get; set; } public string Subject_Title { get; set; } }
每个类中还有许多其他属性.数据库遵循相同的结构.现在我想将分配从数据库映射到视图模型.
我使用automapper编写的映射是第一次工作,但之后没有.因此,Subject的值在后续运行中为null,而Element的值在所有运行中都很好.问题仅限于主题.
任何人都可以指出我正确的方向并告诉我我做错了什么?
Mapper.CreateMap<db_Subject,Subject>(); Mapper.CreateMap<db_element,Element>() .ForMember(dest => dest.Subject,opt => opt.MapFrom(src => src.db_Subject)); Mapper.CreateMap<db_assignment,Assignment>() .ForMember(dest => dest.Element,opt => opt.MapFrom(src => src.db_element));
基本上,db_subject是db_element中的外键,类似地db_element是db_assignment中的外键.在视图模型中,列的名称在某些情况下是不同的.
解决方法
试试这个,
我假设您的数据库类如下所示.
public class DB_Assignment { public DB_Element Db_Element { get; set; } } public class DB_Element { public DB_Subject Db_Subject { get; set; } } public class DB_Subject { public int? Db_Id { get; set; } public string Db_Subject_Title { get; set; } }
然后创建这样的映射
Mapper.CreateMap<DB_Subject,Subject>() .ForMember(destination => destination.Id,options => options.MapFrom(source => source.Db_Id)) .ForMember(destination => destination.Subject_Title,options => options.MapFrom(source => source.Db_Subject_Title)) .ReverseMap(); Mapper.CreateMap<DB_Element,Element>() .ForMember(destination => destination.Subject,options => options.MapFrom(source => source.Db_Subject)) .ReverseMap(); Mapper.CreateMap<DB_Assignment,Assignment>() .ForMember(destination => destination.Element,options => options.MapFrom(source => source.Db_Element)) .ReverseMap();
使用如下
var db_Assignment_1 = new DB_Assignment { Db_Element = new DB_Element { Db_Subject = null } }; var assignment_1 = MappingEngine.Map<DB_Assignment,Assignment>(db_Assignment_1); var db_Assignment_2 = new DB_Assignment { Db_Element = new DB_Element { Db_Subject = new DB_Subject { Db_Id = 1,Db_Subject_Title = "Some title" } } }; var assignment_2 = MappingEngine.Map<DB_Assignment,Assignment>(db_Assignment_2); var db_Assignment_Lst = new List<DB_Assignment> { db_Assignment_1,db_Assignment_2 }; var assignment_Lst = MappingEngine.Map<List<DB_Assignment>,List<Assignment>>(db_Assignment_Lst);
对我来说很好.